1. Field of the Invention
This invention relates generally to a power management system for managing power used and energy consumed in a computer system, particularly a portable computer system where there is often a limit to the peak power that can be supplied and where the energy is usually provided by batteries which have a shorter life if required to deliver increased energy and particularly to a flash disc device which is a memory system having a controller which presents the logical characteristics of a disc storage device to a host, but, which uses a non-volatile semiconductor memory device as its physical storage medium.
2. Description of the Prior Art
Minimizing peak power (where power is energy per unit time) and minimizing energy consumption are sometimes conflicting aims. To minimize the peak power drawn by a Flash Storage System may require that the Flash Storage System takes longer to perform its operations, which can lead to higher energy dissipation since the system is active over a longer period, though at a lower power over this period.
The standard Flash Controller includes a number of hardware blocks. These blocks include a Host Interface Block, a Flash Interface Block and a Microprocessor Block, which are connected to memories via a System Bus. Each of these hardware blocks consumes energy within the Flash Controller. The Host Interface and Flash interface blocks also consume energy on external interfaces. To minimize the energy consumption of the whole computer system requires the minimization of energy consumption within the Flash Controller itself, within the Flash memory, and on the Flash and Host Interfaces.
Thus, a need arises to obviate or mitigate at least one of the aforementioned problems.